The options package

[Tags: library, mit]

The options package lets library and application developers easily work with command-line options.

The following example is a full program that can accept two options, --message and --quiet:

import Control.Applicative
import Options

data MainOptions = MainOptions
    { optMessage :: String
    , optQuiet :: Bool

instance Options MainOptions where
    defineOptions = pure MainOptions
        <*> simpleOption "message" "Hello world!"
            "A message to show the user."
        <*> simpleOption "quiet" False
            "Whether to be quiet."

main :: IO ()
main = runCommand $ \opts args -> do
    if optQuiet opts
        then return ()
        else putStrLn (optMessage opts)
$ ./hello
Hello world!
$ ./hello --message='ciao mondo'
ciao mondo
$ ./hello --quiet

In addition, this library will automatically create documentation options such as --help and --help-all:

$ ./hello --help
Help Options:
  -h, --help
    Show option summary.
    Show all help options.

Application Options:
  --message :: text
    A message to show the user.
    default: "Hello world!"
  --quiet :: bool
    Whether to be quiet.
    default: false


Versions0.1, 0.1.1, 1.0, 1.1, 1.2, 1.2.1,
Change logNone available
Dependenciesbase (>=4.1 && <5.0), bytestring (>=0.9), containers (>=0.1), monads-tf (>=0.1), transformers (>=0.2) [details]
AuthorJohn Millikin <>
MaintainerJohn Millikin <>
Home page
Source repositoryhead: git clone
this: git clone haskell-options_1.2.1.1)
UploadedTue Jan 13 06:05:42 UTC 2015 by JohnMillikin
DistributionsDebian:, LTSHaskell:, NixOS:, Stackage:
Downloads3570 total (41 in last 30 days)
0 []
StatusDocs available [build log]
Last success reported on 2015-01-13 [all 1 reports]




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